like - Turn A cannot be the end of all Gundams literally, Every Gundam couldn't coexist even at the time of release and the logical hoops needed to even try get trickier to jump through with each new deeply fleshed out AU with rich histories of background to fill in for years to come, and it doesn't even try to actually make em all grok together... but it's true in a mythic kinda sense, you know? Turn A is a prophecy of the end for any given value of Gundam, and any given Gundam series's plausible canonicity to it matters only so far as all Gundam continuities cannot exist in perpetuity. they must all end some day, so here is an ending.
and this extends to the Turn A itself too. the Turn A is not the strongest Gundam because it has the highest numbers on the sheet or the strongest ability - it is the strongest Gundam because it is the endpoint of the Gundam as a concept. it beats every Gundam the way death beats every person. the Turn A is a god made manifest with steel and thunder, a figure that strode out of the words of myth, comparable only to the ms it was developed from for which no one knows the origin of in the first place and whose own technology may as well just be Space Magic for how it is replicated-once-but-not-understood. it is, granted, a lot of fun to think about How Would It Fare Against Other God Tier Gundams, but to consider the thought seriously is to miss the forest for the trees - the Turn A wins every fight against any Gundam because its purpose is to set the end of the idea of the Gundam into motion. it does not matter how literally strong it is in the end